1. Field of the Invention
The present invention relates to a semiconductor device and, more particularly, to arrangement of antenna connection electrodes formed on a semiconductor chip used in a radio-frequency identification (RF-ID) system allowing for non-contact data communication with an external unit, and so on.
2. Description of the Related Art
A semiconductor device called RF-ID that communicates with a reader/writer unit has been proposed. The semiconductor device has an antenna for non-contact communication with the reader/writer unit. The antenna is usually provided outside of the semiconductor chip and connected to an electrode formed on the semiconductor chip by bonding or other techniques. Such antennas are referred to hereinafter as external antennas. In recent techniques, the antenna is mounted on the semiconductor chip for the purpose of reducing the size of the semiconductor modules and so on. Such antennas are referred to hereinafter as on-chip antennas.
In the connection of the external antenna, two external antenna connection electrodes are generally placed on the periphery of the semiconductor chip since they are usually connected to the external antenna by bonding.
In the connection of the on-chip antenna, on the other hand, one on-chip antenna connection electrode is placed at the center of the semiconductor chip and the other is placed on the periphery of the chip, for example. A coil-shaped on-chip antenna is connected between these electrodes. Alternatively, as described in Japanese Unexamined Patent Application Publication No. 2001-351082, it has been proposed to form two electrodes (terminals 21A and 22A in FIG. 6 of the above publication) on the periphery of the semiconductor chip and then extend one electrode (the terminal 21A) by rewiring to form an electrode (the terminal 21B) at the center of the chip.
In the semiconductor chip where the two external antenna connection electrodes are placed on its periphery, however, mounting the multi-turn coil antenna requires a multi layer antenna structure since it is unable to connect the antenna between the electrodes with a single layer structure. On the other hand, in the semiconductor chip where the on-chip antenna electrodes are placed at the center and on the periphery, connecting the external antenna has a problem that the electrodes are so close as to cause short-circuit in an antenna connection process.
Further, the configuration shown in Japanese Unexamined Patent Application Publication No. 2001-351082 has a problem of requiring an additional manufacturing process and an extra manufacturing cost to reposition the electrode to the center by rewiring. Besides, since the electrode (the terminal 21A in FIG. 6 of the above publication) after rewiring is covered with an insulating layer, the external antenna should be connected to the terminal (the terminal 22B) on the periphery and also to the terminal (the terminal 21B) formed at the center by rewiring. The electrode at the center and the terminal of the external antenna are apart, causing low yield.
Further, conventional techniques have only proposed the semiconductor chips allowing only exclusive use for either external antennas or on-chip antennas. A semiconductor chip compatible with both external antennas and on-chip antennas has not been invented.